Single-polarity charge sensing in ionization detectors using coplanar electrodes

A new method to preferentially sense the collection of single-polarity charge carriers in ionization detectors is presented. It uses coplanar electrodes to closely emulate the function of Frisch grids commonly employed in gas and liquid ionization detectors. The coplanar electrode structure allows for easy implementation on semiconductor detectors. This method can be used to obtain good energy resolution from detectors in which only one polarity type of carriers is efficiently collected. Experimental results using a CdZnTe detector demonstrate the effectiveness of this method.